A significantly rarer effect than the Fata Morgana happened today at Pole. Based on the wikipedia page for yukimarimo, these were discovered in 1995, but I’m pretty sure people noticed them well before that. Folks have been wintering at Pole for nearly 60 years now, and they occur in some other places where I’d guess they could’ve been seen well before ’95. At any rate, yukimarimo aren’t common – J (who’s a fixture of S Pole winters, having done this ~10 times) told me that they happen about every other year at Pole.

Yukimarimo are little balls of frost, held together by static charge, which get built up and blow across the surface like small tumbleweeds when conditions are just right:

This one might’ve been an inch across

My guess is that they defied official “discovery” for so long because they’re nature’s way of giving photographers the finger: try to take a photo of snow, rolling briskly along across snow, when the atmospheric conditions are in a perfect balance that almost always coincides with dim and flat lighting. Perfect atmospheric conditions include temperatures around -60C, practically ruling out off-camera flash and making photography as uncomfortable as it is difficult.

The round, lighter coloured, dots are yukimarimo

N was on the way back from the Dark Sector and told me about them when he got back to the lab. I dressed up and took my camera outside, then made an announcement over the radio. A few other folks came out to look, but it surprised me how few. We had yukimarimo rolling by for an hour or so today, before the wind picked up a little too much and tore them all apart.